U.S. immigration authorities suspended a program last Friday that expedited visas for skilled workers — a darling class of workers in the tech community.

Despite stoking tension in tech companies, it's a relatively routine decision that's happened under administrations past. But it is missing one key piece of information — a timeline— and that could impact businesses.

What has changed?

"Premium processing" of H-1B visas, which allowed skilled workers to pay extra to request faster approval to work in the U.S., will no longer be available starting April 3, immigration authorities announced. That basically means all applicants will have to wait the standard period to see if they have won the "lottery," without the option to pay an extra $1,225 filing fee for guaranteed answer after 15 days.

Essentially, the government is shifting around which administrative tasks they'll tackle first, said immigration attorney Rajiv Khanna.

"This is not new for anybody. Last year they did the same thing," Khanna said. "It simply means a diversion of resources toward other programs that lack resources."

Indeed, last year immigration authorities said they were delaying premium processing until May 16. But this year's announcement gives a six-month window, not a specific date, for the premium processing delay.

That's where things get tricky.

"At least last year, we knew that by May, the premium track would kick in. It's fair for them to want a month, because they get this flood of applications and go through the lottery process. Getting a month is reasonable," said Piyumi Samaratunga, an attorney at Constangy, Brooks, Smith & Prophete. "[Now] we don't know if it will be implemented in May or at all."

For highly skilled foreign nationals hoping to work in the U.S., the H-1B visa program was already a gamble, as a relatively small number of spots are allocated through a lottery process. Almost all H-1B visa workers start working in October, and that won't change, Khanna said.

H-1B visas applicants must apply six months in advance of their start date — meaning an April 1 application for an Oct.1 start date. Indeed, last year, the H-1B visa program hit its cap for petitions by April 7.

What will change is how fast employers and workers get a "yay" or "nay" on whether they were one of the lucky ones.

Why is this changing?

But the H-1B announcement (not to be conflated with an updated travel ban signed Monday) is closer to a supply chain issue, Samaratunga said.

U.S. immigration authorities said temporary suspension will free them up to sift through a backlog of long-pending applications. That means the majority of visa applicants won't face the long wait times they have in years past.

"The stated intent of the temporary suspension is to clear the backlog, which is an important step for those companies that have been waiting for months," Manan Mehta, founding partner of Unshackled Ventures, a venture capital firm that helps immigrant-founded start-ups deal with immigration issues.

So while it's entirely possible that president Donald Trump will upend the skilled immigration program, this announcement is more of a hiring headache than anything.

Still, immigration lawyer Greg Siskind suggested in a blog post that the change might be a "slow walk" to make H-1B visas a less attractive option, especially in the medical field.

Who is affected?

Employers are first and foremost going to have the toughest time adapting, Samaratunga said.

Let's say an employer extends a job offer, alongside an H-1B visa sponsorship, to a worker, ahead of the April 1 rush. With the fast track option, they could know very soon if their petition was likely to be accepted, and could start planning the onboarding accordingly. If it was likely to be denied, they could begin looking for a new candidate.

But now, they'll have to wait in line, like everyone else. The average wait time is three to six months, Mehta said. So, the employer might not know until September whether their employee will be authorized to work.

The suspension could especially be a sticking point for tech companies that are hoping to get to the cutting edge faster than their competitors. The technology community is in the midst of a talent war, poaching each other's workers and setting up relationships with universities to snare top engineers.

Companies like IBM, Amazon, Microsoft, Google, and Apple have been among the top recipients of H-1B visas in past years, New York Times data analysis shows, aside from a massive swath of visas issued to consulting firms that are known to outsource.

The new delay does mean a little more uncertainty for some workers. Particularly, workers who are on the verge of losing their current visas, and were hoping to have a quick insight into whether they should sign a new lease or pack their bags.

Also affected are H-1B visa applicants that are not subject to the usual cap — especially those working at universities, Khanna said. And a small group of foreign nationals may have to take a break from working while they wait for a visa change to take hold, said Mehta.

Then there are practical inconveniences, like getting one's driver's license renewed or traveling while immigration status is pending, Siskend wrote.

Given all the uncertainty, Samaratunga said, some employers might be more reticint to hire foreign workers — although if they had another choice, hiring a domestic worker is almost always the more practical choice either way, she said.

But there are plenty of loopholes to push through the most urgent cases, Khanna said. Severe financial loss to a company, emergencies, non-profit and humanitarian causes can all still merit requests expedited H-1B visas, Khanna said. And students or H-1B workers changing jobs have special protections to cover the gap while they wait for their new visa to kick in.

Mehta suggested that workers hoping to change their visa status to another type apply to do so by the end of the month to avoid being affected by the suspension.